1. Field of the Invention
The present invention relates to rotary cutting devices and more particularly to cutting devices which by virtue of centrifugal forces align a plurality of filaments in a cutting plane.
2. Description of the Prior Art
The use of rotary cutters in devices like lawn mowers or edgers have been practiced extensively in the past. It is commonly recognized that rigid cutters like blades present a serious hazard to the user of the device and for that reason various attempts have been made in the past to change the configuration of such cutters. One of the more recent developments in the design of such cutters has been the use of filaments which are deployed in a cutting plane by the rotary motion of the cutter and which by virtue of the centrifugal forces thereon are deployed to achieve tip speeds sufficiently great to sever grass strands or similar growth. The advantage of such filament cutters is that the kinetic energy of a single strand is relatively small and therefore any hazard to the user is minimized. By virtue of such low tip kinetic energy, however, the plane of rotation of the filaments is easily disturbed with a consequent distortion of the angular momentum of the cutter assembly and high bending stresses at the point of attachment of the filaments to the cutter assembly. Thus as the rigidity of the cutting element is reduced and cutting action is effected by way of increased tip speed, the concurrent effect is to form a relatively flexible cutting plane which concentrates its flexure stresses at the point of attachment.